LOCATION FIRELAKE                OR

Established Series
Rev. CWL-JVC-JBF
03/2011

FIRELAKE SERIES

The Firelake series consists of very shallow, somewhat excessively drained soils that formed in slope alluvium and residuum derived from tuff-breccia. Firelake soils are on structural benches and hills. Slopes are 2 to 20 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, nonacid, mesic Lithic Xeric Torriorthents

TYPICAL PEDON: Firelake very gravelly loamy coarse sand--on an east facing slope of 6 percent at an elevation of 1,405 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 5 cm; light brownish gray (10YR 6/2) very gravelly loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak thick platy structure parting to moderate medium granular; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine and common fine interstitial pores; 30 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 13 cm thick)

Bw1--5 to 13 cm; brown (10YR 5/3) gravelly coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to strong medium granular; soft, very friable, slightly sticky and nonplastic; few very fine and few fine roots; common very fine and common fine interstitial pores; 15 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (5 to 10 cm thick)

Bw2--13 to 18 cm; pale brown (10YR 6/3) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few very fine and few fine roots; few very fine and few fine interstitial pores; 15 percent gravel; slightly alkaline (pH 7.7); abrupt smooth boundary. (0 to 8 cm thick)

R--18 cm; hard, slightly fractured tuff-breccia.

TYPE LOCATION: Lake County, Oregon; about 7 miles south of Buffalo Well and 100 yards west of jeep trail; approximately 900 feet south and 1,150 feet west of the northeast corner of section 22, T. 28 S., R. 20 E.; USGS Buffalo Well 7.5 minute topographic quadrangle; latitude 43 degrees 07 minutes 56 seconds N and longitude 120 degrees 19 minutes 53 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture Usually moist in winter and spring, dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 9 degrees C.
Depth to bedrock: 10 to 25 cm to a lithic contact.
Other features: Combined thickness of the Bw horizons is only 5 to 13 cm. The Bw horizons do not constitute a cambic horizon because combined thickness does not meet minimum thickness requirement of 15 cm.

Particle-size control section - Clay content: Averages 6 to 16 percent.
Sand content: Averages 60 to 75 percent total with more than 30 percent very coarse sand through medium sand;
Rock fragments: Averages 15 to 25 percent, mainly gravel. Lithology of fragments are tuff-breccia or basaltic tuff.

A horizon
Chroma: 2 or 3, dry or moist.
Structure: Granular or platy parting to granular.
Organic matter: 0.1 to 0.4 percent

Bw1 horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3 dry, 2 through 4 moist.
Textures: Gravelly coarse sandy loam or gravelly sandy loam.
Clay content: 8 to 16 percent.
Rock fragments: 15 to 30 percent.

Bw2 horizon (when present)
Value: 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Sandy loam or gravelly sandy loam.
Clay content: 10 to 16 percent.
Rock fragments: 10 to 20 percent.

COMPETING SERIES: These are the Onepennee and Schawana series.

Onepennee soils have 30 to 50 percent sand in the particle-size control section and are slightly acid or neutral. Schawana soils have less than 35 percent very coarse sand through medium sand and have mean annual soil temperature of 12 to 13 degrees C.

GEOGRAPHIC SETTING: Firelake soils are on structural benches and hills. These soils formed in slope alluvium and residuum derived from tuff-breccia or basaltic tuff. Minor amounts of loess and volcanic ash are also components of the parent materials. Slopes are 2 to 20 percent. Elevations range from 1,375 to 1,555 meters. The climate is arid with cold, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm, mean annual temperature is 7 to 9 degrees C, and the frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brace, Boilout, Enko, and Rabbithills soils. Brace soils fine-loamy, moderately deep to thin duripans over lithic contacts, and have argillic horizons. Boilout soils have argillic horizons and are shallow to thin duripans over lithic contacts. Enko soils are coarse-loamy and very deep. Rabbithills soils are loamy, shallow to duripans, have cambic horizons, and do not have bedrock within 150 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; very high surface runoff; moderately rapid permeability; high saturated hydraulic conductivity.

USE AND VEGETATION: Firelake soils are used for livestock grazing. The native vegetation is mainly basin big sagebrush, Thurber's needlegrass, Indian ricegrass, and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 5,500 acres of the series mapped to date. MLRA 23.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Lake County (Northern Part), Oregon, 2006. The name is from a local feature.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A, Bw1, and Bw2 horizons).
Lithic contact - The boundary at 18 cm to underlying, unweathered hard bedrock (R layer).
Particle-size control section - The zone from the soil surface to 18 cm (A, Bw1, and Bw2 horizons).

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National Cooperative Soil Survey
U.S.A.